CoffeeScript in Action

432 Pages·2014·10.77 MB·English

by  Patrick Lee

Patrick Lee
M A N N I N G
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CoffeeScript in Action
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CoffeeScript in Action
PATRICK LEE
MANNING
SHELTER ISLAND
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ISBN: 9781617290626
Printed in the United States of America
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brief contents
PART 1 FOUNDATIONS . ............................................................1
1 ■ The road to CoffeeScript 3
2 ■ Simplified syntax 13
3 ■ First-class functions 45
4 ■ Dynamic objects 76
PART 2 COMPOSITION ..........................................................105
5 ■ Composing objects 107
6 ■ Composing functions 144
7 ■ Style and semantics 179
8 ■ Metaprogramming 214
9 ■ Composing the asynchronous 241
PART 3 APPLICATIONS...........................................................267
10 ■ Driving with tests 269
11 ■ In the browser 299
12 ■ Modules and builds 321
13 ■ ECMAScript and the future of CoffeeScript 353
v
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contents
preface xv
acknowledgments xvi
about this book xvii
about the cover illustration xxi
PART 1 FOUNDATIONS. .................................................1
1 The road to CoffeeScript 3
1.1 Why CoffeeScript? 4
1.2 Running CoffeeScript 5
1.3 JavaScript 6
C 6 ■ Scheme 7 ■ Self 7
1.4 Evolving JavaScript 8
A little story about language 8 ■ The lesson for JavaScript 9
1.5 Creating CoffeeScript 9
Designing new syntax 9 ■ Achieving new syntax 11
1.6 Summary 12
vii
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viii CONTENTS
2 Simplified syntax 13
2.1 Your first program 14
Comparing CoffeeScript to JavaScript 14
2.2 Simple expressions 16
Literal values 16 ■ Variables 18
2.3 Operators 18
Essentials 19 ■ Types, existential, and
combining operators 23 ■ Exercises 25
2.4 Statements 25
Anatomy 25 ■ Statements as expressions 26
Pure statements 30 ■ Exercise 31
2.5 Strings 31
Methods 31 ■ Interpolation 32 ■ Exercise 33
2.6 Arrays 33
length, join, slice, and concat 34 ■ in 35
Ranges 35 ■ Comprehensions 36 ■ Exercise 39
2.7 Heres for comments, docs, and regexes 39
Comments 39 ■ Heredocs 40 ■ Heregexes 41
2.8 Putting it together 41
Running in a browser 41 ■ Running on the command line 42
2.9 Summary 44
3 First-class functions 45
3.1 Computation 46
Basics 46 ■ Custom operations 47 ■ Anatomy 48
Comparison: JavaScript and CoffeeScript 52 ■ Exercises 52
3.2 Events 53
Browser events 53 ■ Using timeouts and intervals
to create events 54
3.3 I/O 56
Ajax 56 ■ Event-driven file reading with Node.js 57
Event-driven file serving with Node.js 58 ■ Exercises 59
3.4 Higher-order functions 59
Invoking other functions 60 ■ Example: Counting words
in a file 61 ■ Functions as arguments 62 ■ Exercises 65
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CONTENTS ix
3.5 Scope 66
Lexical function scope 66 ■ No block scope 66
Implicit variable declarations 67 ■ Nesting 68
3.6 Closures 70
Global state problems 70 ■ Functions as return values 70
Extended example: using closure 72
3.7 Putting it together 73
3.8 Summary 75
4 Dynamic objects 76
4.1 Syntax 77
Literals 77 ■ Properties 77 ■ YAML-style syntax 78
4.2 Key-value stores 78
Data 79 ■ Key-values for named arguments 82 ■ Exercises 84
4.3 Comprehensions 85
Object comprehensions 85 ■ Example 87
4.4 Structured data 89
JSON 89 ■ Trees 89
4.5 Binding 91
this 91 ■ The fat arrow 94
4.6 Prototypes 96
Copy 96 ■ Object creation 97 ■ Exercises 98
4.7 Behavior 98
Refactor 99 ■ Exercise 100
4.8 Classes 100
Declaration 101 ■ Object identity 102 ■ Exercises 103
4.9 Putting it together 103
4.10 Summary 104
PART 2 COMPOSITION...............................................105
5 Composing objects 107
5.1 Being classical 108
Raw data 108 ■ Class abstractions 109
5.2 Class inheritance 112
extends 112 ■ How does it work? 114
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